Spectroscopy textbookwritten by Cal Poly Pomona's very own Dr. Phil Beauchamp! Also, Dr. Beauchamp created a useful guide for interpreting Mass Spec fragmentation patterns.
Identifying solvent peaks in NMR spectra: see tables in the following JOC journal article ("NMR Chemical Shifts of Common Laboratory Solvents as Trace Impurities"
H. E. Gottlieb,*, V. Kotlyar, A. Nudelman* Journal of Organic Chemistry199762 (21), 7512-7515.)
ChemCalcMass Spec calculator (determines possible formulas, given a molecular or fragment mass)
"ChemCalc: a building block for tomorrow’s chemical infrastructure." Patiny, Luc; Borel, Alain Journal of Chemical Information and Modeling201. DOI: http://dx.doi.org/10.1021/ci300563h
Spectral Database SDBS - find available spectra for a given compound (IR, NMR, Mass Spectrum)